The first known epidemic of poliomyelitis in Easton, Pennsylvania, occurred in 1949, and was unusual in the high proportion of paralytic to non-paralytic cases. Both poliomyelitis and Cosxackie, or C, viruses were isolated from more than half the patients studied during the acute stage of the disease. One month later C virus was only occasionally recovered. Classification of the 28 strains of C virus which were isolated revealed that 24 belonged to one antigenic type, Easton-2 (related to Albany type 1 virus).
Patients from whom C virus was isolated showed a rise during convalescence to the Easton-2 or homologous type antibody. Two patients with paralytic poliomyelitis were studied for the quantitative development of antibodies to the poliomyelitis virus and to the C virus found in their stools. Using the neutralization test in monkeys and in newborn mice, respectively, a simultaneous rise in antibodies to both agents was observed.
The situation at present can be summarized as follows:—Poliomyelitis virus or C virus may produce infection in man, with a specific antibody response. Both agents may be carried, particularly in the intestines, without causing any serious illness and healthy carrier states have been observed for each. Both viruses can be found in nature in flies and in sewage. However there has been no evidence to suggest that these two viruses bear a relationship to each other, even when isolated from the same patient. Thus, when both viruses are found in a patient with paralysis, it is not yet possible to say with any degree of accuracy to what extent each is responsible in the over-all pattern of the disease. How frequently dual infections of this nature may occur remains for future investigations to determine. Certainly all cases of poliomyelitis are not complicated by a superimposed infection with a C virus. However, this will have to be one more item to consider in epidemic poliomyelitis.